PostGIS  2.5.0beta1dev-r@@SVN_REVISION@@

◆ cluster_within_distance_garray()

Datum cluster_within_distance_garray ( PG_FUNCTION_ARGS  )

Definition at line 2956 of file postgis/lwgeom_geos.c.

References ARRAY2LWGEOM(), array_nelems_not_null(), cluster_within_distance(), gserialized_from_lwgeom(), linemerge(), LW_SUCCESS, lwgeom_free(), lwgeom_geos_error(), PG_FUNCTION_INFO_V1(), and SRID_UNKNOWN.

Referenced by clusterintersecting_garray(), pgis_abs_out(), and pgis_geometry_clusterwithin_finalfn().

2957 {
2958  Datum* result_array_data;
2959  ArrayType *array, *result;
2960  int is3d = 0;
2961  uint32 nelems, nclusters, i;
2962  LWGEOM** lw_inputs;
2963  LWGEOM** lw_results;
2964  double tolerance;
2965  int srid=SRID_UNKNOWN;
2966 
2967  /* Parameters used to construct a result array */
2968  int16 elmlen;
2969  bool elmbyval;
2970  char elmalign;
2971 
2972  /* Null array, null geometry (should be empty?) */
2973  if (PG_ARGISNULL(0))
2974  PG_RETURN_NULL();
2975 
2976  array = PG_GETARG_ARRAYTYPE_P(0);
2977 
2978  tolerance = PG_GETARG_FLOAT8(1);
2979  if (tolerance < 0)
2980  {
2981  lwpgerror("Tolerance must be a positive number.");
2982  PG_RETURN_NULL();
2983  }
2984 
2985  nelems = array_nelems_not_null(array);
2986 
2987  POSTGIS_DEBUGF(3, "cluster_within_distance_garray: number of non-null elements: %d", nelems);
2988 
2989  if ( nelems == 0 ) PG_RETURN_NULL();
2990 
2991  /* TODO short-circuit for one element? */
2992 
2993  /* Ok, we really need geos now ;) */
2994  initGEOS(lwpgnotice, lwgeom_geos_error);
2995 
2996  lw_inputs = ARRAY2LWGEOM(array, nelems, &is3d, &srid);
2997  if (!lw_inputs)
2998  {
2999  PG_RETURN_NULL();
3000  }
3001 
3002  if (cluster_within_distance(lw_inputs, nelems, tolerance, &lw_results, &nclusters) != LW_SUCCESS)
3003  {
3004  elog(ERROR, "cluster_within: Error performing clustering");
3005  PG_RETURN_NULL();
3006  }
3007  pfree(lw_inputs); /* don't need to destroy items because GeometryCollections have taken ownership */
3008 
3009  if (!lw_results) PG_RETURN_NULL();
3010 
3011  result_array_data = palloc(nclusters * sizeof(Datum));
3012  for (i=0; i<nclusters; ++i)
3013  {
3014  result_array_data[i] = PointerGetDatum(gserialized_from_lwgeom(lw_results[i], NULL));
3015  lwgeom_free(lw_results[i]);
3016  }
3017  pfree(lw_results);
3018 
3019  get_typlenbyvalalign(array->elemtype, &elmlen, &elmbyval, &elmalign);
3020  result = construct_array(result_array_data, nclusters, array->elemtype, elmlen, elmbyval, elmalign);
3021 
3022  if (!result)
3023  {
3024  elog(ERROR, "clusterwithin: Error constructing return-array");
3025  PG_RETURN_NULL();
3026  }
3027 
3028  PG_RETURN_POINTER(result);
3029 }
uint32_t array_nelems_not_null(ArrayType *array)
void lwgeom_free(LWGEOM *geom)
Definition: lwgeom.c:1144
#define LW_SUCCESS
Definition: liblwgeom.h:79
int cluster_within_distance(LWGEOM **geoms, uint32_t num_geoms, double tolerance, LWGEOM ***clusterGeoms, uint32_t *num_clusters)
Takes an array of LWGEOM* and constructs an array of LWGEOM*, where each element in the constructed a...
LWGEOM ** ARRAY2LWGEOM(ArrayType *array, uint32_t nelems, int *is3d, int *srid)
void lwgeom_geos_error(const char *fmt,...)
#define SRID_UNKNOWN
Unknown SRID value.
Definition: liblwgeom.h:187
GSERIALIZED * gserialized_from_lwgeom(LWGEOM *geom, size_t *size)
Allocate a new GSERIALIZED from an LWGEOM.
Here is the call graph for this function:
Here is the caller graph for this function: